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Borland Style Graphics
for Dev C++)
Mr. Dave Clausen
La Cañada High School
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The Text Screen
The text screen contains 25 lines with a
capacity of holding 80 columns of textual
characters.
80 X 25 = 2,000 positions
But there are actually over 2,000 positions on
a display screen.
The screen consists of pixels (picture
elements) that it uses to represent the textual
characters and symbols.
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Graphics Setup Here are the steps that you need to follow
to use “Borland Style Graphics” source code in Dev C++:
1. Tell the compiler that graphics commands will be used.
2. Initialize the Graphics Screen
3. Close the graphics screen after you have finished drawing your graphics.
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Graphics Setup 2 1) To tell the compiler that graphics
commands will be used, include the
preprocessor directive:
#include <graphics.h>
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Graphics Setup 3• 2) To initialize the graphics screen
initwindow(640,480);
After you are finished drawing, you need to use the
while(!kbhit()); command to leave the picture on
the screen, or use cin.get();
The last choice requires: #include <iostream.h>
• 5) Then close the graphics screen, using:
closegraph( );
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Fundamentals
of
Graphics
The Graphics Screen.
Color Options.
Graphics Mode.
Drawing Lines
Line Style
Clearing the Screen.
Plotting Points.
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If you have a VGA graphics card or better
in your computer, then the graphics screen
has 640 pixels across and 480 pixels
down.
640 X 480 = 307,200 pixels
The upper left corner is position (0, 0)
The lower right corner is position
(639, 479)
• Remember, the computer starts counting with
zero.
The Graphics Screen
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The Graphics Screen
Dimensions
(0, 0) (639, 0)
(0, 479) (639, 479)
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You can select the color of the background.
This is done before drawing anything in the foreground (otherwise your drawing will disappear.)
To select the background color use the command.
setbkcolor(number); Where (number) is a numeric constant from 0
through 15, or the symbolic constant that represents the color.
Background
Color Options
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Color Options
You select a foreground or “drawing” color by
using the following command:
setcolor(number);
• Where (number) is a numeric constant from 0
through 15, or the symbolic constant that
represents the color.
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Color Names
Here are the color numbers and names:
0 = BLACK
1 = BLUE
2 = GREEN
3 = CYAN
4 = RED
5 = MAGENTA
6 = BROWN
7 = LIGHTGRAY
8 = DARKGRAY
9 = LIGHTBLUE
10 = LIGHTGREEN
11 = LIGHTCYAN
12 = LIGHTRED
13 = LIGHTMAGENTA
14 = YELLOW
15 = WHITE
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Drawing Lines
The Current Pointer.
The current pointer is an invisible pointer
that keeps track of the current pixel
position. It is the equivalent of the visible
cursor in text mode.
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To move the pointer to a location on the graph without drawing anything, use the command:
moveto (X,Y); This is like PenUp (PU) in LOGO
To draw lines from the current pointer’s position to another point on the graph, use the command:
lineto (X,Y);
This is like PenDown (PD) in LOGO or SetXY (x, y)
grtmplte.cpp
Drawing Lines 2
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Graphics Figures
•Lines
•Rectangles
•Circles
•Arcs
•Ellipses
•Points
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Lines, The Easy Way
Instead of using the commands: moveto
and lineto, we can draw a line using one
command:
line(x1, y1, x2, y2);
The points (x1, y1) describe the beginning
of the line, while (x2, y2) describes the
endpoint of the line.
The numbers x1, y1, x2, y2 are integers.
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Rectangles
Rectangles can be drawn in different ways
using lineto, moveto, moverel, and linerel.
But an easier and faster way is using the
Rectangle procedure which draws a rectangle
in the default color and line style with the
upper left at X1, Y1 and lower right X2, Y2.
rectangle (x1, y1, x2, y2);
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Circles
Circles can be drawn using the circle
procedure.
This draws a circle in the default color and
line style with center at X, Y, radius in the X
direction of Xradius, and corresponding Y
radius.
circle (x, y, radius);
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Arcs
This procedure draws a circular arc in the
default color and line style based upon a circle
with center X, Y and given X radius.
The arc begins at an angle of StartAngle and
follows the circle to EndAngle. The angles are
measured in degrees from 0 to 360 counter-
clockwise where 0 degrees is directly right.
arc ( x, y, startangle, endangle, radius);
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Visualizing Arcs
Starting & Ending
Angles
0
90
180
270
Starting AngleEnding Angle
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EllipsesDraws an elliptical arc in the default color and
line style based upon an ellipse with center X,
Y and given radii.
The arc begins at an angle to Start Angle and
follows the ellipse to End Angle. The angles
are measured in degrees from 0 to 360 counter-
clockwise where 0 degrees is directly right.
ellipse ( x, y, startangle , endangle, x_radius, y_radius);
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Plotting Points The Maximum value for X can be
found using:
getmaxx( )
The Maximum value for Y can be found
using:
getmaxy( )
To Plot a point:
putpixel ( x_value, y_value, color);
For example: putpixel (100, 100, WHITE);
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Sample Program
Let’s look at a program with a line,
rectangle, circle, arc, ellipse, and a point.
Objects.cpp
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Line Style
Setting the line style.
All lines have a default line mode, but
Turbo C++ allows the user to specify three
characteristics of a line:
style, pattern, and thickness.
Use the command:
setlinestyle (style, pattern, thickness);
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Line Style
and
Thickness Names
Here are the names of the line styles and
thickness:
Line Style Thickness
SOLID_LINE NORM_WIDTH
DOTTED_LINE
CENTER_LINE THICK_WIDTH
DASHED_LINE
USERBIT_LINE
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Line Style Patterns
The names of the line patterns are:
SOLID_LINE = 0
DOTTED_LINE = 1
CENTER_LINE = 2
DASHED_LINE = 3
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Filling Patterns
•Selecting Pattern and Color
•Filling Regions
•Getting a Pixel
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Selecting Pattern
and Color
Use the command SetFillStyle for setting the
pattern and color for the object that you wish
to fill.
setfillstyle ( pattern, color);
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Pattern NamesHere are the name of available patterns:
Values Causing filling with
EMPTY_FILL Background Color
SOLID_FILL Solid Color
LINE_FILL Horizontal Lines
LTSLASH_FILL Thin diagonal lines
SLASH_FILL Thick diagonal lines
BKSLASH_FILL Thick diagonal backslashes
LTBKSLASH_FILL Light backslashes
HATCH_FILLThin cross hatching
XHATCH_FILL Thick cross hatching
INTERLEAVE_FILL Interleaving lines
WIDE_DOT_FILL Widely spaced dots
CLOSE_DOT_FILL Closely spaced dots
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Filling Regions
After selecting a color and pattern,
floodfill is used to fill the desired area.
floodfill ( x, y, border_color );
This “paints out” the desired color until it
reaches border color.
Note: The border color must be the same
color as the color used to draw the shape.
Also, you can only fill completely
“closed” shapes.
Program10_4.cpp
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To draw a filled ellipse:fillellipse ( xcoordinate, ycoordinate, xradius, yradius);
To draw a filled rectangle:
bar (x1, y1, x2, y2);
To draw a filled 3D rectangle:
bar3d(x1, y1, x2, y2, depth, topflag); //depth is width of
the 3D rectangle, if topflag is non-0 a top is added to the bar
To draw a filled section of a circle:pieslice (x, y, startangle, endangle, xradius);
Filling “Special” Regions
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Text Output on the Graphics Screen
To write a literal expression on the
graphics screen using the location
specified by (x, y) use the command:
outtextxy (x, y, “literal expression”);
outtextxy (x, y, string_variable);
Note: These are not “apstring” type
strings. They are C++ standard Strings.
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To set the values for the text characteristics, use:
settextstyle ( font, direction, charsize);Font Direction
DEFAULT_FONT HORIZ_DIR = Left to right
TRIPLEX_FONT VERT_DIR = Bottom to top
SMALL_FONT
SANS_SERIF_FONT Fonts continued
GOTHIC_FONT COMPLEX_FONT
SCRIPT_FONT EUROPEAN_FONT
SIMPLEX_FONT BOLD_FONT
TRIPLEX_SCR_FONT
Text Styles
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CharSize
1 = Default (normal)
2 = Double Size
3 = Triple Size
4 = 4 Times the normal
5 = 5 Times the normal
….
10 = 10 Times the normal
Text Styles
Font Sizes
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To set the way that text is located
around the point specified use the command:
settextjustify (horizontal,vertical);
Horizontal Vertical
LEFT_TEXT TOP_TEXT
CENTER_TEXT BOTTOM_TEXT
RIGHT_TEXT
Program10_2.cpp
Text Justification
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Clearing the Screen
Here is the way to clear the graphics
screen.
When in graphics mode use:
cleardevice( ); //#include <graphics.h>
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Returns the height, in pixels, of string S if it
were to be written on the graphics screen
using the current defaults.
textheight (S string);
Returns the width, in pixels, of string S if it
were to be written on the graphics screen
using the current defaults.
textwidth (S string);
Text
Height & Width
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Getting a Pixel
To return the color number corresponding to
the color located at the point: X, Y use the
command:
getpixel (x, y);
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Useful Non Graphic Commands
kbhit()
• checks to see if a keystroke is currently
available
• If a keystroke is available, returns a nonzero
integer.
• If a keystroke is not available, returns a zero.
Any available keystrokes can be retrieved
with getch().